1. Field of the Invention
The invention relates to a light converging system, more particularly to an LED light converging system based on imaging techniques.
2. Description of the Related Art
The development of light-emitting diodes (LED) is becoming more mature nowadays, and their application to lighting devices is more and more common. In applying the LED to projectors, how to effectively collect the diverging source light provided by the LED is an important issue to be researched and developed upon. In addition, since the angular range of the source light provided by the LED is large, it is difficult to use the LED as a point light source.
Conventional light source systems for projectors can be categorized into two groups. One type of conventional light source systems utilizes ultra-high pressure (UHP) arc lamps and an array of lenses to converge and homogenize light. This type of conventional light source system requires a large-sized reflector, and the source light provided by such a system contains a large amount of ultra-violet light and infrared light, which can damage other optical components in the projectors and shorten the service lives thereof. The other type of conventional light source systems utilizes integration rods for light-homogenization. The integration rod needs to be sufficiently long to ensure higher efficiency in homogenizing light. Moreover, this type of conventional light source system requires a set of transmission lenses disposed to receive homogenized light exiting the integration rod for further projection, which results in a corresponding increase in the size of the projectors equipped with such a system.